Signify is a neat little Perl program that allows a semi-random email
signature to be generated from a set of rules.  You can create multiple
sections where each section can be one of an unlimited number of
possibilities, each with its own weighting so those really cool quotes
can appear more often than others.  Sections can be placed next to each
other vertically to create columns.  You can even format each section
independently as left/right/center and top/bottom/vcenter.

Some email clients, such as Mutt, can be made to automatically invoke
signify when you write a new email message.
